Blog of Web Developer Garry Pilkington

(ASP.Net, C#, AngularJs, JavaScript, HTML5 & UWP)

Wow what a title, but it does explain that this post covers debugging the full .net framework application (not .net core) running on a Server Core container (not Linux) from the comfort of a Windows 10 Pro machine running Visual Studio 2015 and Docker for Windows.

Running remote tools on a machine and attaching is a pretty straight forward task, but there a re a few hurdles in the way when doing it on Windows Server Core 2016 container, but once it is scripted it is pretty painless.

Firstly we need a decent Docker image to start with, luckily the guys at Microsoft have created the Microsoft/aspnet image we can start with so lets build up our dockerfile

FROM microsoft/aspnetRUN mkdir C:\site

This gets the base image and creates directory that we are going to use for our web files.

This section is completely optional and all it does is install the web management tools for remote administration. You may want to tweak the container settings such as application pool and start and stop it from the GUI on your Windows 10 machine. If you are not bothered about IIS settings, then you can omit this section.

This copies the directory permissions set up for the wwwroot directory and assigns it to the site directory, so we don’t end up with nasty permission denied issues.

EXPOSE 8000 8172 4020 4021

We need to expose 8000 for our web application, 8172 for remote IIS admin and 4020 and 4021 are the ports we need opening for remote debugging tools. Visual Studio 2015 remote tools use these ports, other versions use different ports and as yet I cannot find the ports for Visual Studio 2017.

Next we locate our dockerfile using a cmd prompt and run docker build

docker build -t iis-site .

It will take a while to run through and will be quicker in future builds as you will already have the layers that make up the final image.

This creates a container based on our previous iis-site image and creates a mapping to a directory on our Windows 10 machine to the site directory we created in the dockerfile; this container will have the name web1.

This gives me 172.19.184.110 and yours will be different as each container gets its own address. We know we are on port 8000 so open up a browser and browse to your home page:-

Great, now lets get debugging. In future releases of Visual Studio 2017 it will be possible to debug straight into a Windows container, but at the moment it is limited to Linux containers, so we need to do a bit more configuration.

Once downloaded, put the .exe in the same directory as your web application on your machine as that is already visible to the container. There are ways to automate the download using Invoke-WebRequest, but I had several issues with resolving the url so it was easier to do it myself.

Create a .bat file with the following and copy that also into the web application directory on your machine:-

rtools_setup_x64.exe /install /quiet

Get the id of the container by using the command:-

docker ps

With the id, lets open an interactive cmd prompt:-

docker exec -it 03a8eb766d5a cmd

Where 03a8eb766d5a is my container identifier.

Run the bat file:-

install-tools.bat

This will take a couple of minutes to run through, but when it is finished you can cd to the C:\Program Files\Microsoft Visual Studio 14.0\Remote Tools directory to take a look.

This will start the remote debugging service msvsmon and your cmd prompt will just sit quiet with no cursor.

So now open up the web application in Visual Studio and go to Debug >> Attach to process

Click on the Find button and it should find your container with its id and ip address showing, simply select it.

Now we need to make sure we choose Managed (v4.6, v4.5, v4.0) code or whatever version of the framework you are using. Also make sure show processes from all users is checked.

Scroll down and choose w3wp and attach. Check the security warning and then start debugging as you would normally do.

Ideally it would be best if the remote tools could be downloaded as part of the build and the starting of msvsmon be automatic when F5 in Visual Studio. If you are happy with your container, you could save it as an image using the command:-

Containers on Windows 10

This is part 1 of what will most likely be a series (unless I get totally hacked off with containers like I am right now). Part of the series will be about getting containers up and running on a Windows 10 box to run a Windows based container. Then I will progress onto Windows Server 2016 and get the same configured container to run on that and hopefully discover some kind of work flow for developers along the way. The end game is to develop a website using Visual Studio 2015, test on Nano Server running IIS and deploy using Server 2016.

Pre-requisites.

Apart from Windows 10 professional or Enterprise, you need to be sure you are running at least the Anniversary Update (1607); to check this go to a command line and type:- winver

I am running 1607 build 14393.187 (22nd September 2016)

Enable Containers

To get containers installed, you need to enable the feature. This can either be done using PowerShell or the UI. Here is the PowerShell:-

Enable-WindowsOptionalFeature -Online -FeatureName containers -All

Then as Windows 10 will only support Hyper-V containers, enable that feature as well:-

Installing Docker

As of Docker version 1.12 there is an option to download Docker for Windows, however to natively run Windows containers instead of using MobyLinux as a middle ware virtual machine, opt to install the beta version which can be found here:- https://docs.docker.com/docker-for-windows/

Switch to Windows Containers

Once installed, right click the whale and switch to using Windows Containers.

Now you can get the version of Docker and it should show that both host and client are running windows.

It will take a while to download if it has not already been cached on your host machine.

List the images

To list the images you have on your host use the command:-

docker images

Run Nano Server

This can be achieved simply by using the docker run command; however if you want to run it interactively you can append the –it flag and get into a command line like this:-

docker run –it microsoft/nanoserver cmd

Once it starts up you will be in the command line of the container; you can check this by using the hostname command.

You can get out of this container by typing exit and it will get you back to your host machine. Once there use the command docker ps and it will list all running containers and you will see there are none running now. You can however use the switch –a to get all containers in both running and stopped state.

As you can see I have a lot of containers, but thats ok I can delete them all by iterating through them all and remove using the rm command like this:-

Following on from the previous post where we already have a container that can run a static website inside IIS, this post will configure IIS to run a simple MVC website and deploy an application into it.

Setting up Containers for MVC Web Applications

So by calling Get-Container and Get-ContainerImage we should have our ServerCoreIIS container switched off and our 2 base images.

Firstly we are going to create a new container that will end up being our base image for MVC applications, so call the New-Container command like this:-

When it is done you will be back at the PowerShell prompt and you shouldn’t need to reboot the container.

Exit out of the PowerShell session and stop the container. Now we need to create an image from this container, so call the Get-Container and pipe it to the New-ContainerImage command similar to what we did in the last post:-

Now you have an image of Server Core with IIS and MVC that you can create all future containers from.

Deploy an MVC application to a container

You may have a different method of how to deploy an application to a container, but for simplicity for this exercise I have a network share that I have copied an out of the box Visual Studio MVC application into. So create a new container from the IISMvc image.

Creating an IIS Base Image for Containers

Now we have a base image from the last post, we can use it to create other images and containers. Enter a PowerShell command and call Get-ContainerImage, we should see our WindowsServerCore image.

For the sake of this demonstration we will let our containers get an IP address from DHCP in the network, other situations will lead to different DHCP configurations with the containers and their IP address as completely throw away.

So again in the host machine create a new VM switch, I have it mapped to my External switch which will handle the DHCP.

New-VMSwitch –Name DHCP –NetAdapterName Ethernet

Now we create a new container which will become our base IIS image, so call

Windows Server 2016 Containers

Containers, Docker and other similar technologies are such a trending topic these days I thought I would take the time to have a look at what all the fuss is about. Being a Windows developer and not completely happy with having to run VirtualBox just to get a Linux distro working so I can create a container, With Windows Server 2016 containers are built in so I wanted to explore them and see how it could change my development workflow. These posts are a journey of installing and configuring a set of containers to host an ASP.Net MVC website inside them. I initially tried running the PowerShell scripts linked by Microsoft on their ‘Windows Containers Quick Start’ pages, but I ended up getting so many errors with them (it is understandable as it is still in development) that I started from scratch and built the containers up myself.

Installing Windows Server Core and enabling the Container feature

Firstly get the Server 2016 ISO from https://aka.ms/tp4/serveriso. Currently this is Technical Preview 4 and may change before the final release of Windows Server 2016.

I have renamed my ISO WindowsServerTP4 so I can find it on my machine much easier.

Create a VM and mount the ISO as the DVD drive.

Make sure the VM has access to an external switch.

I have called mine ContainerHost and will be a Server Core installation.

Start and connect to the Virtual Machine.

Follow the usual UELA and drive specifics.

On first boot you need to change the password (use tab to move to the confirm password prompt).

Enter a PowerShell session.

Install the Container Windows feature by using the cmdlet

Install-WindowsFeature Containers.

Server will continue to install components during reboot.

Login and renter back into PowerShell.

Now you can list all the command the Container feature exposes.

Run Get-Command –Module Containers

Installing a Base OS Image

The main container features are now installed, however all containers must be based off an OS image and these come from OneGet. As Server Core Technical Preview 4 is version 10.0.10586.0, then the base OS image has to be the same. These images are WIM files and can be downloaded and saved to your local network from the Server Core Virtual Machine. First install the PackageProvider (OneGet).

Install-PackageProvider ContainerProvider –Force

Then you can use this to find container images from OneGet.

Find-ContainerImage

Create a local share on your host machine and create a mapped drive in the Virtual Machine.

This will take a long time depending on your internet connection as it is Gigabytes in size.

Now the wim file is on your host network you can use the Install-ContainerOSImage to import it to your image collection. This way any time you want to create other Virtual Machines and run through this process again, you already have the WIM and don't need to download it again. However the WIM version will change if there is another Technical Preview or Release.

Running the command Get-ContainerImage should list this as an OS image.

In the next post I will create an image that has IIS set up and then create containers based off this image.